One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,9)(8,10)(11,12)(15,19)(18,20)(21,22)(23,24)(25,30)(26,27)(28,29)(31,32)(33,36)(34,35) involution — undirected(5,7,8,11)(6,9,10,12)(14,17)(18,20)(22,27)(23,29)(30,35)(31,33)(6,10)(9,12)(13,14,16,17)(15,18,19,20)(21,23)(22,28)(24,27)(25,33)(26,29)(30,32)(31,34)(35,36)(1,2)(3,4)(5,6)(7,9)(8,10)(11,12)(21,24,26,28)(22,29,27,23)(25,32,34,36)(30,33,35,31)(5,7)(6,9)(8,11)(10,12)(13,15,16,19)(14,18,17,20)(21,25)(22,30)(23,31)(24,32)(26,34)(27,35)(28,36)(29,33)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.